Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
, 6, 21270

In Situ Characterization of the Local Work Function Along Individual Free Standing Nanowire by Electrostatic Deflection

Affiliations

In Situ Characterization of the Local Work Function Along Individual Free Standing Nanowire by Electrostatic Deflection

Yicong Chen et al. Sci Rep.

Abstract

In situ characterization of the work function of quasi one dimensional nanomaterials is essential for exploring their applications. Here we proposed to use the electrostatic deflection induced by work function difference between nanoprobe and nanowire for in situ measuring the local work function along a free standing nanowire. The physical mechanism for the measurement was discussed in details and a parabolic relationship between the deflection and the potential difference was derived. As a demonstration, measurement of the local work functions on the tip and the sidewall of a ZnO nanowire with Au catalyst at its end and a LaB6 nanowire have been achieved with good accuracy.

Figures

Figure 1
Figure 1. Principle of the method.
(a) Schematic diagram of the measurement. When the probe moves approach different positions of the nanowire with a distance of d, charge Q can be induced at the corresponding position due to their work function difference. As a result, a bending deflection x of the nanowire can be caused due to their electrostatic attractive force. By adjusting the external voltage V, their potential difference can be eliminated and there will be no electrostatic deflection. (b) SEM image of the measurement where the insets are (c) the enlarged SEM image and (d) the TEM image of the nanowire.
Figure 2
Figure 2. The relationship between the electrostatic force F1 and the force F2 required to overcome the elastic energy.
F1 and F2 are represented by the orange and blue curves respectively. With a different value of formula image, F1 can be intersecting (solid line) or tangent (dash line) with F2.
Figure 3
Figure 3. The relationship between equation (4,5).
Equation (4,5) are represented as the green and red curves respectively. Although their converging form is different, they own the same vertex and symmetry axis.
Figure 4
Figure 4. Measurement results on a ZnO nanowire.
(a,c) are series of SEM images of the measurement on the Au particle and the sidewall region below it at a ZnO nanowire respectively with different external voltage V. (b,d) are their corresponding results of d – x versus the external voltage. The red curves are the results fitting by a parabola function, which show that their CPDs are 0.58 V and 0.17 V respectively when comparing to the Au-coated probe. The insets are the corresponding schematic diagrams of the measurements.
Figure 5
Figure 5. Measurement result on a LaB6 nanowire.
(a,c) are series of SEM images of the measurement on the tip and the sidewall of a LaB6 nanowire respectively with different external voltage. (b,d) are the corresponding results of d − x versus V. The red curves are the results fitting by a parabola function, which show that their CPDs are 0.74 V and 0.76 V respectively when comparing to a tungsten probe. The insets are the corresponding schematic diagrams of the measurements.

Similar articles

See all similar articles

Cited by 2 articles

References

    1. Duan X., Huang Y., Cui Y., Wang J. & Lieber C. M. Indium phosphide nanowires as building blocks for nanoscale electronic and optoelectronic devices. Nature 409, 66–69 (2001). - PubMed
    1. Cui Y. & Lieber C. M. Functional Nanoscale Electronic Devices Assembled Using Silicon Nanowire Building Blocks. Science 291, 851–853 (2001). - PubMed
    1. Bonard J.-M., Dean K. A., Coll B. F. & Klinke C. Field Emission of Individual Carbon Nanotubes in the Scanning Electron Microscope. Phys. Rev. Lett. 89, 197602 (2002). - PubMed
    1. Colinge J.-P. et al. Nanowire transistors without junctions. Nature Nanotech. 5, 225–229 (2010). - PubMed
    1. Mongillo M., Spathis P., Katsaros G., Gentile P. & Franceschi S. D. Multifunctional Devices and Logic Gates With Undoped Silicon Nanowires. Nano Lett. 12, 3074–3079 (2012). - PubMed

Publication types

Feedback